The long-term goal of the DRC Immunoassay Core is to improve human health by supporting clinical laboratory testing services for research in diabetes mellitus. Since the last competitive review, Washington University School of Medicine has consolidated clinical research testing into the Core Laboratory for Clinical Studies (CLCS), and the DRC Immunoassay Core is fully-integrated into CLCS. This administrative change substantially improves the operational efficiency ofthe DRC Immunoassay Core and provides DRC investigators access to more automated instruments, better-trained personnel and improved quality control procedures. Importantly, institutional support for clinical research testing is focused through CLCS, and the DRC Immunoassay Core leverages this substantial support. CLCS provides expert consultation to investigators so that the most appropriate tests can be chosen while taking cost and number of samples into consideration. DRC investigators are not limited to a fixed menu of tests. Classic metabolic analytes such as insulin and glucagon as well as custom assays such as adiponectin or TNF-a are subsidized. Many other analytes are determined in CLCS at cost. CLCS has a contract with Quest Diagnostics at substantial cost savings for analytes not done at CLCS. Development of new research tests is an important goal. CLCS is currently investigating mouse insulin and plasma VEGF-a (vascular endothelial growth factor alpha) using digital single molecule counting, a promising new technique for materially improving ELISA sensitivity. CLCS is also active in validation of common laboratory analytes for FDA review under industry-sponsored contracts. Developmental research provides equipment and a level of skill that helps investigators both directly and indirectly.